Twelve letterpress copybooks, primarily with Cameron writing as assistant to T.J. Potter but also as vice-president of the B&NW, and B&W. Most letters pertain to engineering and construction, concerning WA&N, the C&N Wis, the Chillicothe & Kansas City, and Chicago, St. Paul and St. Louis roads. Also includes a letter to C.E. Perkins urging the building of a line from Chicago to St. Paul and including estimates of revenue.